I'll be getting a DX50 in the mail probably Monday or Tuesday so I'll be able to see how they compare. I think the plan right now is to keep the X3 to use with my UERM and the DX50 hopefully will be with my next custom which I plan for it to be the V6 Stage.

[Impression] FiiO X3

I can now share my first impressions having got mine yesterday. As a J3 user I was really surprised (in a good way) with the form and build of this player - solid with the feel of quality. Similar size to the J3 but thicker and noticeably heavier (I wouldn't want to drop this!). My windows 8 PC had no problem detecting it and I transferred some stuff to the internal storage and borrowed the filled SD card from my J3. Nice touch that a dummy head album has been thrown in for free by the way.

The screen and interface are perfectly ok in use - everything looks good, scrolling is smooth albeit slightly slower than the J3's touchscreen, however the buttons feel positive in use. Volume adjustment is a big improvement from the J3. The button positions bearing in mind they are all the same shape will take some getting used to however.

As others have said, browsing by tag is not that good yet as when you select artist you just get a long list of every track (Not sorted into albums). Best to browse by album or by folder structure for the time being as maybe this will be fixed in a firmware update.

Incidentally the first thing I did was update to current firmware and this was effortless as I already had the file on a spare memory card that I'd taken out of an old phone!

Album art is showing inconsistently - you just have to have it named as cover.jpg in the J3 but with the X3 it has to be embedded - work to be done here by me although maybe this will be changed by firmware in the future.

Lastly the sound impressions - I won't go into detail as the X3's characteristics have been described already by better reviewers than me. All I can say is that I am totally blown away by how much better this sounds compared to my J3. Using ACS T1 IEM's the improvement is far from subtle with my existing 16 bit FLAC's, and every aspect of reproduction has been taken to a higher level. What's great is that this is with minimum adjustment of EQ - the J3 only ever sounded good for me with loads of complex adjustments - this sounds good out of the box. I have a few 24 bit albums and these sound better still ( I had only ever listened to those before on my Nexus phone).

So for anyone with a J3 wondering whether the X3 is worth considering, I can assure that you won't be disappointed with how this DAP sounds. I was originally considering keeping this alongside the J3, but will now be selling the J3 without hesitation. I will use a portable charger for the few occasions I need more than 10 hours battery life (long haul flight next month). 64gig card comes on Monday!Edited by phillevy - 9/15/13 at 3:37am

I was stunned by my fully modded x3 , it's just too good for its price range. Having a wider soundstage and warmer sound signature without any detail loss. Simply an amazing DAP. The only weakness is the GUI is relatively laggy when I am switching the song or browsing folders, anyways it doesn't the playback so I would consider it is a minor issue.

I think Chinese DAP can strike a balance between technical specification and product design. Nice spec is always nice but product design is directly affecting the user experience.I think FiiO is doing pretty well towards this approach.

I was stunned by my fully modded x3 , it's just too good for its price range. Having a wider soundstage and warmer sound signature without any detail loss. Simply an amazing DAP. The only weakness is the GUI is relatively laggy when I am switching the song or browsing folders, anyways it doesn't the playback so I would consider it is a minor issue.

I think Chinese DAP can strike a balance between technical specification and product design. Nice spec is always nice but product design is directly affecting the user experience.I think FiiO is doing pretty well towards this approach.

Most common mod is replacing AD8397 opamp with AD8620.
I believe there are better suitable opamps available and the next weeks I am going to test out OPA1602, OPA1612 and LMH6643 and decide wheter or not I am going to replace the AD8397.